Rotary fluid pump or motor



Dec. 3, 1929. 1 PAGEL 1,737,942

ROTARY FLUID PUMP OR MOTOR Filed Nov. 18, 1926 '6 Sheets-:Sheet 1 24 5Dec. 3, 1929. T. J. PAGEL 1,737,942 VRO'IARY FLUID PUMP on MOTOR FiledNov. 18, 1926 e Sheets-Sheet 2 g? a 7 WW Dec. 3, 1929. I 12.1. PAGEL 942ROTARY FLUID PUMP OR MoToR Filed Nov. 18, 1926 s Sheets-Sheet 5 1929- T.J. PAGEL ROTARY FLUID PUMP 0R MOTOR 6 Sheets-Sheet 4 Filed Nov. 18, 1926EEEE:

Dec. 3, 1929. 'r. J. PAGEL 1,737,942

ROTARY FLUID PUMP on MQTOR Filed Nov. 18, 1926 6 Sheets-Sheet 5 Dec. 3,1929. T. J. PAGEL ROTARY FLUID PUMP OR MOTOR 6 Sheets-Sheet Filed NOV.18, 1.926

Patented Dec. 3, 1929 UNITED sr'A'ra eai'raur oFFi-ca THEODORE J. PAGEL,MINNEAPOLIS, MINNESOTA, ASSIGNOB TO ?A.GEL ROTARY- PUMP MANUFACTURINGCOMPANY, OF MINNEAPOLIS, MINNESOTA, A CORPORA- TION OF MINNESOTA.

ROTARY FLUID PUMlP B. MOTOR Application filed November 18, 1926. SerialNo. 148,130.

My lnvention has for its object to provide an improved rotary fluid pumpor motor; and to this end, my invention consists of a rotary fluid pumpor motor having embodied therein the novel devices and combinations ofdevation of the complete pump, or motor, do

vices hereinafter described and pointed out in the claims.

My invention, in its preferred form is illustra'ted in the accompanyingdrawings,

wherein like notations refer to like parts throughout the several views.4

In the said drawings Fig. 1 is a front ele- Fig. 4, is a verticallongitudinal section on the irregular line l-r-l; of Fig. 3. 4 Fig. 5 isa'vertical cross section on the line 5-5 of Fig. 4.

Fig. 6 is a View, partly in plan and partly Fig. 3. Fig. 7 is a verticalcross section on the line 7-7 of Fig. 1.

' Fig. 8 is a detail, showing one of the piston' 9 blades detached, inend elevation.

Fig. 9 isa plan view of one of the piston blades detached. Fig. 10 is aview, in side elevation, looking at one of the end liner plates of thecylinder detached. i

Fig. 11 is an end view of the same. Fig. 12 is an end elevation of thecylinder liner detached. 5 Fig. 13 is a side elevation of the same.

Fig. 14 is a left end elevation of the piston 4 body detached.

Fig. 15 is a front elevation of the same.- Fig. 16 is a View similar toFig. 3, showing a modification in respect to the arcuate length of theconcentric loaded chamber of the pump or motor. v

Figs. 17 and 18 are assembled views, illustrating a modified form ofstructureof the rotary fluid pump or motor, said Figure 17 being acentral cross section on the line 1717 in horizontal section, on theline 6-6 of" of Fig.18, and Fig. 18 being a vertical longitudinalsectlon on the line 18-18 of Fig. 17.

Fig. 19 is a side elevation of one ofthe end I liner plates, employed inthe pump shown in Figs. 17 and 18, detached.

, ig. 20 is a detail in section, showing one of the valves forcontrolling the waste. ducts of the pump illustrated in Figs. 17 and 18.

, The chief features of-novelty embodied in my improved pump or motorreside in the special form of the cylinder bore, the structure andrelations of the piston to said bore, and the especial relations of thepiston blades to the supply and discharge passages of the cylinder; butthese special features can be most conveniently pointed out after theelements of the general structure have first been identified.

" General stmotwr'e The numeral 21 represents a flanged .cyl-

'inder casting or housing of such structure, at

its base, as to adapt the same to be bolted fast to a suitablesupporting bed not shown. This cylinder casting 21 has a suitable intakepipe coupling nipple 22 and a suitable discharge pipe coupling nipple 23properly spaced apart from each other. The numerals 24 represent a pairof reciprocally similar flanged end castings, adapted to be bolted fastto the flanged cylinder casting 21. The numeral 25 represents the istonshaft, and the numeral 26 the piston ody rigidly secured thereto. Theclinder end castings 24 are provided with tlnnged hubs 27, through whichthe shaft 25 passes, at which points it is packed by suitable stuflingboxes 28. The said cylinder end cast ings 24 are provided with outwardlypro ecting spider-like arms 29, adapted to hold and support, between thesame suitable ball-bearing devices 30 for the'outer end portions of thepiston shaft 25. To prevent endwise movement of'the piston and itssupporting shaft 25, there is applied thereto what may be termed apiston stabilizer. As illustrated, this includes the following detailsto-wit:-

One end of the piston shaft 25 is reduced to Y adapted to be bolted tothe ends of the hearing arms 29 of the adjacent cylinder end casting.24. The sections of the divided bearing block 32 are keyed fast toathehousing 33 and are adapted to be clamped tightly together, by the bolts34, as best shown in Fig. 5. Inasmuch as the housing 33 is bolted fastto the bearing ends of the arms 29 of the cylinder casting 24, it, ofcourse, cannot move laterally, or lengthwise of the piston shaft; andinasmuch as the sections of the divided bearing block 32 are rigidlysecured in this housing 33, as just last above noted, it follows thatthey cannot move lengthwise of the piston shaft; and inasmuch as thesegrooved sections of said bearing block 32 embrace the collar 31 of thepiston shaft 25, said shaft and the piston fixed thereto are positivelyheld from any endwise motion. This stabilizer, therefore, keeps thepiston in its proper working position within the cylinder.

As shown, the said housing 33 of the stabilizer serves as the outerretaining plate for the adjacent ball bearing devices 30, on which theadjacent end of thepiston shaft 25 rotates. The housing 33 is,.ofcourse, properly constructed for the application of lubrication. Thesaid housing 33 has an opening in line with the axis of the piston shaft25, adapted to be closed by a plug 35, as shown in Fig. 4, which affordsaccess to the interior of said housing 33 and the adjacent end of thepiston shaft 25, for applying a suitable device, to determine the rotaryspeed of the piston, whenever so desired.

The piston body 26 is provided with a series of equally spaced slot-likeseats 36, extending inward from its periphery, for seating acorresponding series of blades 37 ada ted to move gugward beyond theperiphery 0 said piston The numeral 38 represents a cylinder'liner orbushing, adapted to closely fit the interior of the cylinder casting 21,being applied thereto with a driving fit, and which is rigidly securedthereto, by means which will be present- I ly noted, to prevent rotationthereof in respect to said cylinder casting. The numerals 39 represent apair. of end wall liners for the cylinder, having therein apertures 40properly located for adapting the liners to be slipped over the pistonshaft 25. Each of said end liners 39 has a diameter equal to theinterior diameter of the cylinder casting 21, and the peripheral edgesof said liners 39 are adapted to be clamped between the cylinder casting21 and said cylinder end castings 24, when said parts are properlybolted together, as best shown in Fig. 4. A locking key 41 longer thanthe cylinderliner 38, is provided, and this key is adapted to be seatedin keyways formed one-half of each thereof in the cylinder casting 21and the other halvesflin the cylinder liner 38 and the end liners 39.The half key slot of the cylinder casting 21 is marked with the numeral42; the half key slot in the cylinder lining 38 is marked with thenumeral 43 and the two half key slots in the end liners 39 are markedwith thenumeral 44. In addition to locking the said three linerstogether and to the cylinder casting, the key 41 also serves as aconvenient means for properly positioning said three liners in respectto the cylinder casting, when assembling the parts into their properworking positions. The cylinder end castings 24 are of such structure,on their inner rofile faces, as to afford, on each thereof, a uid orsupply passage 45 communicating with the intake nipple 22 of thecylinder and a fluid discharge passage 46 communicating with thedischarge nipple of the cylinder; and these said.passages 45 and 46 areseparated, at their opposite ends, by bridge walls marked with referenceletters A and B, said bridge wall A being between the ending of thedischarge passages 46 and the beginning of the supply passages 45 andsaid bridge wall B being between the ending of the supply passages 45and the beginning of the discharge passages 46.

Because of the fact that the said fluid supply passages 45 and dischargepassages 46, formed in the cylinder end castings 24 by recessing theirprofile faces, as best shown in Figs. 4, 6 and 7, it follows that therespective co-operative pairs of these passages communicate with eachother over the peripheries of the cylinder castings 21 and c linderliners 38 in position to afford a latera delivery of the fluid to thecylinder and a lateral discharge of the fluid from the cylinder of thepump or motor, at

points inward of the peripheries of the cyl-- inder casting 21 and thecylinder liner 38 and outward of the piston body 26. Because of theserelations of these parts, it follows that no openings need to beprovided in the peripheral walls of the cylinder castings .21 or theperipheral walls of the cylinder 38; and, because of these last namedfacts it further follows that the outer ends of the piston blades 37will always contact with a continuous unbroken bore wall, therebyminimizing the wear and tear on the outer end of said piston blades andon the bore wall of the cylinder.

The cylinder end liners 39, in the portions .thereof opposite saidsupply and discharge cavities 45 and 46 of the end castings24, areprovided with perforations to permit the fluid to pass through saidliners, in its flowage into and out from the chambers between the wallsof the cylinder and the piston body. The particular perforations of saidliners 39 which permit the inward passage of the fluid from said supplycavities 45 are marked with the reference numeral 47, as shown in Figs.3, 4, 6, 1'0 and 16; and the particular perforations of said liners 39which permit the outward passage of the fluid into the dischargecavities 46 are marked with the numeral 48, as shown in the same views.In other words, the porstruction and so positioned that they will tendedfunctions.

tions of said liners 39 having the said perforations 47' and 48, whentheparts are assembled, stand located directly opposite to and incommunication with their respective co-operating supply cavities 45 anddischarge cavities 46 formed in the cylinder end castings 24, and saidperforations 47 and 48 are separated by bridge walls marked with thereference letters A1 and B, Said bridge walls A and B on the lines 39correspond to the bridge walls A and B on the cylinder end castings 24,and are similarly located when the parts are assembled, to-wit, thebridge wall A is directly aligned with the bridge wall A and the bridgewall B is directly aligned with the bridge wall B.

The said end liners 39 are also eachprovided, on their inner profilefaces, with two ducts which, on account of their function,

(later to be noted) may be called equalizing ducts, one of which ismarked with the numeral 49 and the other thereof with'the numeral. 50,as best shown in Fig. 10. These equalizing ducts 49 and 50 are of suchconcommunicate with the inner ends of the pistons blade seats 36,throughout certain portions of the pistons travel, as will hereafter bemore particularly pointed out, for purposes which will then more fullyappear. The said equalizing ducts markedv 49 communicate constantly withthe intake fluid passages 45 of the cylinder end castings 24by means ofspecial perforations 51 in the end liners 39; and the ducts 5Ocommunicate con-' stantly with the discharge cavities 46 of the cylinderend castings 24 by means of special perforations 52 in the end liners39, as shown in Figs. 4, 6, and 10. Said equalizing ducts 49 and 50 ofthe liners 39 are separated by bridge walls marked C and D, as bestshown in Fig. 10, so as to prevent intercommunication thereof. If theliners 39 were dispensed with, then these equalizing ducts 49 and 50would be formed in the cylinder end castings 24, in proper positions toperform their in- The blade seats 36 of the piston body 26 are rabbeted,at their forward parts of this motor or pump which are subect to thegreatest wear or tear, or the greatest deterioration from other causessuch as the corrosive character of the fluid which may be handled by thepump or motor.

For the purposes of considering the most vital features of theinvention, however, the

pump or motor may be treated ,as if these liners were absent, assumingthat the cylinder end castings thereof should have formed thereon thesaid equalizing ducts 49 and 50. For example, in the structureillustrated, the cylinder bore is afforded by the inner wall of thecylinder liner 38, but, if that liner was abderstood that the expressioncylinder bore and the expression cylinder walls are used in a broadsense so as to apply equally .well whether the said liners 38 and 39 arepresent or absent.

Special features of the cylinder and piston measured on a straight linedrawn through the piston center; and the axis of the piston bodyoccupies such a position that the pe riphery of the body willapproximately contactwith the bore of the cylinder, at a placeintermediate the ending of the discharge passages and thebeginningof theintake passages of the pump. In the structures illustrated, this placeof approximate contact between the piston body and the cylinder bore islocated between the cylinder nipples 22 and 23, and is marked on .thecylinder bore with the letter X. At this place X of approximate contactbetween the piston body and the cylinder bore, the piston body itselfmay afiord the needed seal between the discharge and intake sides of thepump, or reliance may be placed on the piston bladesto effect this seal,depending upon the kind of fluid being handled by the pump. At this sameplace X of the cylinder bore, the end walls of the piston or the endwalls of the piston blades, or both together, afford theineeded sealbetween the said parts and the. end walls of the cylinder. The bridgewalls A between the fluid supply ports 45 and discharge ports 46 of thecylinder end castings 24 are located opposite to'and in proper alignmentwith this place X of the cylinder bore, and the same remarks apply withrespect to the coresponding bridge wallsA of the end liners 39.

The cylinder bore of this improved pump or motor is made up. of twosurfaces, one or which is concentric to the piston center, and the otherof which is non-concentric to the piston center. The concentric portionof said bore is formed on an are generated from the piston center with aradius equal to the radius of the piston body plus the extreme outerthrow of the piston blades,

'ton.

and this concentric arc is of a length equal to, or greater, than thearcuate distance between any two successive blades of the piston. Theopposite arcuate extremities of the concentric arc of the cylinder boreare indi cated on the drawings by the reference letters Y and Z. Thisconcentric arc YZ of the cylinder bore is located so as to be betweenthe delivery end portions of the fluid supply cavities of the cylinderend castings 24, and the receiving end portions of-the fluid dischargecavities 46 of said cylinder castings in proper alignment with thebridge walls 13 of the liners 39, or the bridge walls B, of the cylindercastings 24 (if the liners are absent), which'bridge walls form the sidewalls to the space or chamber between the piston body and the cylinderbore spanned by this concentric arc of the bore, and the arcuate lengthof these bridge walls B or B is of'a length equal to or greater than thearcuate distance between successive blades of the pis- The said bridgewalls B or B co-operate with the piston body and blades toalford theneeded seal in the travel of the piston through this concentric are Y4-Zof the cylinder bore. Because of its function, this said chamber spannedby said concentric are YZ of the cylinder bore may be called forconvenience of distinction, the concentric loaded chamber of the pump.,

The non-concentric portion of the cylinder bore extends from and joinsthe opposite extremities of the said concentric arc YZ; and no point ofthe said non-concentric part of the bore is at a greater distance fromthe center of the piston than the radius of the concentric arc, and nopoint thereof is at a less distance from the piston center than theradius of the piston body; or, in other words, this non-concentricportion of the cylinder bore extends from the point Z to the point Y andpasses through the point X of the cylinder bore, and the portion thereofextending from the point X to the point Y diverges outward from thepiston body and the portion thereof extending fromthe point Z to thepoint X converges inward towards the piston body. The said place X maybe said to divide the said non-concentric portion of the cylinder boreinto two sections, one of which spans what may be called thenon-concentric loading chamber of the pump, extending from X to Y, andthe other of which may be called the non-concentric unloading chamber ofthe pump extending from Z to X. The end walls of these non-concentricloadingand unload,- ing chambers are afforded by the perforated portions'47 and 48 of the end liners 39, when said liners are present, and bythe portions of the cylinder castings 24 having therein the fluid intakeand fluid discharge passages 45 and 46, if said liners 39 are absent,and, hence it follows that the said loading chamber is always in lateralcommunication with the fluid supply passages and that the said unloadingchamber is always in lateral communication with the fluid dischargepassages of the pump. The said s-o-called loaded chamber spanned by theconcentric arc YZ of the cylinder bore communicates with the saidloading and unloading chambers only under the control of the pistonblades; and, in View of the number and disposition of said piston bladesand the arcuate length of said concentric portion of said cylinder bore,above noted, one or more of the piston blades will always operate toefiect a seal between the receiving and discharge sides of the saidloaded chamber YZ and will receive no motion 'relativeto the piston bodywhile traveling through the major part of said loaded chamber and nonewhatever, at any part of said arc, unless it be at the single instantwhen the blades enter that arc and the blade seats 36 begin tocommunicate with the equalizing ducts 50.

In the foregoing, it has been assumed that the piston blades 37 willtake their outermost position under the effect of centrifugal forcearising from the rotation of the piston. After said piston blades passbeyond the point Z of the concentric are YZ, their outer ends will ridein contact with the non-concentric part of the cylinder bore, extendingfrom Z to X and which converges toward the periphery of the piston body,and hence the blades will, under the'piston travel, be cammed inwardthereby to their inward camming limit,

on reaching the point of the cylinder bore.

movement of the piston blades 37, the equalizing ducts 49 and 50 havebeen provided in the end liners 39 (and which might be on the endcastings 24, if the liners 39 were absent) As hitherto stated, theequalizing ducts 49 are in constant communication with the intakepassages 45 of the cylinder and castings 24 and the otherequalizingducts 50 are in constant communication with the dischargepassages 46 in the cylinder end castings. During the travel of thepiston blades 37, from the point X to the point Y, the inner ends of theblade seats 36, formed in the piston body 26, will travel by andcommunicate with these equalizing ducts 49 and 50 in succession. Morespecifically stated, while the as of shorter length than in the otherviews,

point Y the inner ends of said blade seats 36 will be in communicationwith the ducts 49, thereby rendering the intake fluid pressure availableon the inner ends of said blades, and, as their outer ends communicatewith the fluid intake passages 45 at this time, the pressures areequalized on all surfaces of these blades and the blades are balanced.Then under the continued travel of the piston, as soon as the inner endsof the blade seats pass the bridges D of the liners 39, they will beginto communicate with the equalizing ducts 50, thereby rendering dischargefluid pressure available on the inner ends of the blades, while theblades are passing through the loaded chamber or from Y to Z, whichpressure will hold the blades in their outermost position, and, if anyof the blades are not in their outermost position, when they enter thisloading chamber, the said fluid pressure available from the dischargeside of the pump through the duct 50, will immediately force the sameinto their outermost position. Then, under the continued travel of thepiston, the inner ends of the blade seats 36 will keep in communicationwith the duct 50 approximately" until they reach the point X, andbridges C, of the liners 39; and, it follows that, as soon as saidblades pass the point Z or the concentric are or from the loaded to theunloading chamber of the cylinder, the fluid pressures on all surfacesthereof will be equal, or in other words the said blades will bebalanced and the (Jamming-surface of the non-concentric part of thecylinder bore, in the unloading chamber ZX will only be calledupon gomove the blades inward against centrifugal 'orce. Y

It has already been stated that the length of the concentric are YZ ofthe cylinder bore and the bridge walls B and B must be equal to orgreater than the arcuate distance between successive blades of thepiston, The reason for this limitation is-that, otherwise, it would notnecessarily follow that at least one of the piston blades would beavailable in the loaded chamber to afford a seal between the loading andunloading chamber. There may be more than one of these blades so act ingin the loaded chamber, at the same time, but there must be at least oneso available, or otherwise there would be a time when the loading andunloading chambers would directly communicate with each other, throughthe concentric loaded chamber. In the main views, the concentric arc Y-Zis of such length that there will be, at times, more than one of thesaid piston bladesacting as a seal in the loaded chamber YZ; but,in theslight modification illustrated in Fig. 16, the can centric arc Y--Zofthe cylinder bore is shown but nevertheless is of a length equal tothe distance between the successive blades of the piston thereillustrated; and, in that modification there will always be one of saidblades acting in said loaded chamber to afford the needed seal betweenthe loading and the unloading, chambers. Of course, the bridge Walls Bof the end castings 24 and the bridge Walls B of the cylinder liners 39,will be of corresponding arcuate length equal to the concentric arc ofthe cylinder bore in this modification shown in Fig. 16. Thismodification has'been illustrated simply to make clear the minimumlength of said concentric arc portion of .any cylinder bore, that mightbe employed in a pump or motor having a piston with eight blades spacedapart v:trom each other, as illustrated in the drawings. In theforegoing description, the cylinde bore has been stated to be made up ofa portion, which is concentric to the center of the piston generatedwith a radius equal to the radius of the piston body plus the extremethrow of the piston blades, and a portion non- ,concentric to the pistoncenter with all surfaces thereof at no greater distance from the centerof the piston than the radius of the concentric arc and no portionthereof at a less distance from the piston center than the radius of thepiston body; and that statement was correct, but was used simply to getthe essentials of that part of said bore expressed in the mostgeneralized form of statement. Having regard, however, to the particularstructure illustrated in the drawings, a simpler statement can be made.

Assuming that the concentric are Y-Z of the cylinder here has beendetermined in the inanner heretofore described, then, ifthat concentricarcbe bisected by a straight line which, when extended, will passthrough the center of the piston, and, being further extended will passthrough the periphery of the pistons body, it will determine the point Xof the bore and there will be three determined points available, to-wit,X, Y and Z, through which a circle can be drawn; and, if a point be thenselected on said arc-bimeting line equi-dist'ant from said three pointsX, Y and Z, itwill be a point eccentric to the piston center and thedistance thereof from any of the points X, Y and Z may be used as aradius for generating a circle which will pass through said three pointsand afford an eccentric contour to the non-concentric part of thecylinder bore. It will follow, of course, that the portions of theeccentric part of the cylinder bore extending from X to Y and from X toZ, respectively, will be equal to each'other'in arcuate length and thatthe spaces between the walls of the piston body the cylinder end wallsand the cy 1- inder bore spanned by said eccentric arcs 'X-Y and XZ willbeef equal "volume capacity and will diverge away from the piston bodyequally in opposite directions from the said point X, This simple planwas followed .in generating thef'non-concentricportion of the cylinderbore of the pump illustrated. It will, however, be understood that thesaid non-concentric part of the cylinder bore does not need to begenerated in that particular way, and this is the reason that the moregeneralized form of statement has been employed in the foregoingportions of the general description and will be employed in the claimsor some thereof.

So far as I know, I am the first to have provided in any rotary fluidpump or motor a loaded chamber concentric to the piston center ofrotation, and I also believe that I am the first to have provided anymeans for rendering fluid pressure available to balance the pistonblades or to hold the same in their outermost positions while travelingthrough said loaded chamber. The presence of these new features afford apump of great efi'iciency and economy of operation. The pis-' tonblades, when traveling through the loaded chamber or under loads,receive, practically, no motion in respect to the piston body, and, atall other times, when they do receive any motion in respect to thepiston body,.they are balanced, and it follows that they are easy tomove, and that the wear and tear on the piston blades, so far as that,depends on,

the sliding motion in their seats, is reduced to a minimum. Itis alsoobvious that .less driving power is needed to rotate the piston thanwould be required, if the piston blades were not balanced. The presenceof said concentric loaded chamber, with a concentric arc of properlength, in combination with the piston having blades of the propernumber and properly spaced, relative to the length of this concentricare, also enable a much more reliable seal to be procured between theloading and unloading chambers of the pump or motor.

Having regard to the capacity of the pump, for any predetermined speedof the rotary piston, in a given unit of time, that depends upon thecubical interior capacity of the concentric loaded chamber, which, ofcourse, is determined by the dimensions of the cooperating parts of thecylinder and the piston. The desired capacity is taken as the startingor fixed factor in the designing of the pump.

In the structure illustrated in Fig. 16 there is neither lap nor lead,in the relations of the loaded to the loading and unloading chambers,but in the structure shown in Figs. 1 to 15, inclusive, lap and lead arepresent.

Some further'details as to the general structare It may first be notedthat, in the structure illustrated in Figs. -1 to 16 inclusive, thepisating parts of the cylinder and the piston. center but areapproximately tangential to a circle generated from the pistons centerwith a radius equal to the distance between the piston center and theoilset or eccentric center from which the non-concentric part of thecylinder bore is generated. The reason why the said seats 36 are soformed is that it is thought the centrifugal force will be moreeffective on the blades, for forcing them .into their outermostposition, than if the traveling through the loaded chamber.

As another detail, it may be noted that the cylinder end castings 24 areprovided with waste ducts 54 leading from the space be tween the pistonshaft 25 and the hubs 27 of the cylinder end castings to the fluidintake passages 45 formed in said cylinder end castings, as best shownin Fig. 7 of the drawings. The purpose of these waste ducts 54 is toprovide a means which will draw oif any fluid which leaks through fromthe fluid passages of the pump into the space around the shaft betweenthe liners and the cylinder end castings adjacent to the stufling boxes28. It is obvious that, due to the presence which the piston shaft 25passes, thus being in a position to catch any fluid which may leakthrough said stuffing boxes and direct the same to off-leading pockets55 formed in the base portions of the cylinder end castings 24, as bestshown in Fig. 4.

Modification Referring now to the modification illustrated in *Figs. 17to 19 inclusive, thevnumeral 56 represents the cylinder casting and thisis provided with intake coupling nipple 57 and discharge coupling nipple58. The

numerals 59 represent the cylinder end cast- 63 the piston body. Thepiston body is provided with radial seats- 64 for the piston blades 65.The outer contacting ends of these piston blades are rounded instead ofbeing beveled as in the main structures shown in the other views. Thecylinder casting 56 is so constructed as to aflord fluid supply passages66 in'communication with the intake coupling nipple 57, and so as toafford fluid discharge passages 67 in communication with the outlet ordischarge nipple 58, as best shown in Fig. 17. For this purpose thecylinder casting 56 is enlarged outward, at the proper places to affordthese fluid passages 66 and 67. The cylinder liner-60 is provided, onits exterior or periphery, with two corresponding sets of fluid passagesafi'orded by pairs of slots in the periphery of said liner, the supplymembers of which are marked with the numeral 68 and the dischargemembers of which are marked with the numeral 69. I The said sup plyslots 68 are in constant communication with the supply passages 66 ofthe cylinder casting, and the discharge slots 69 are in constantcommunication with the discharge passage 67 of the cylinder casting; andthese slots 68 and 69 are located so as to be in registering alinementwith said passages 66 and 67 of said cylinder casting, as best shown inFig. 17. The said pair of'slots 68 are.

convergent from about the point X to the point Y of the cylinder bore,and the pair of slots 69 are so formed as to be convergent from thepoint X to the point Z of the cylinder bore. This special arrangement ofsaid slots 68 and 69 is made so as to secure more uniform wear on theouter ends of the piston blades 65, for one thing, and, for another to Isecure a better distribution of the fluid passing therethrough. 4

The cylinder bore of this modification is formed in the same way as thebore of the cylinder in the inain views, and the piston body is relatedto the cylinder bore in the same way. The cylinder liners 61 areprovided with equalizing ducts 70 and 71, which correspond in functionto the equalizing ducts 49 and 50 of the cylinder liners 39 of thestructure shown in the main views The ducts 70 are in constantcommunication, the slots 68 of the cylinder liner, with the fluid supplypassage 66 of the cylinder casting; and the ducts 71 are in constantcommunication, through the slots 69 of said liner, with the dischargepassage 67 of the cylin- (lcr casting. The said ducts 70 and 71 have thesame relation to the seats 64 of the piston blades as do the ducts 49and 50 of the cylinder liner 39 to the blade seats of the piston shownin the main views. These parts all co-operate in the same way as setforth in respect to the structure of the main Views. The chiefdifl'erence is that, this modified structure affords a radial intake anddischarge of the fluid instead of-a lateral intake and discharge, asprovided in the structure of the main views. The piston blade seats alsodiffer slightly from the blade seats shown ceiving and discharge ends ofsaid ducts, and I by the use thereof the said ducts may be entirelyclosed or opened to their largest extent. If these ducts are open, theywill be subject tothe pumping action of the piston blades available fromthe supply passage 66, and,

hence, anyfiuid which seeps through to the stufling boxes 7 3 will bedrawn into the receiving or loading chamber of the pump.

Hence, it is possible to prevent the accumulation of undesired seepagepressure, at the stufling boxes 7 3. or.to regulate the same to anydesired pressure.

Having regard to the equalizing ducts 49 and 50 on the end liners 39,and and 71 on.

the end liners 61, it should be noted-that the respective members of theco-operating pairs of these ducts should have a volumetric content orcapacity equal to that of the space in blades, at the time when theblades are in their outermost position.

Having regard to said cylinder liners 39, it should be noted thatinasmuch as the fluid can only get into andnut of the cylinder throughthe perforations 47 and 48 of these liners, and into and out of theequalizing ducts 49 and 50, through the perforations 51 and 52 of theseliners, it :tollows that the said perforated liners operate as strainersfor the fluid and thereby exclude from the cylinder injurious materials,such as pieces of metal or stones, which might otherwise break the pumpor motor.

Having regard to the sediment trapping grooves 53 of the piston body,formed by rabbeting the outer edges of the blade seats 36, as hithertostated, it is obvious that, under the travel of the piston, thesegrooves will catch or trap any sand, grit or other sediment, which-mayget into the cylinder and carry the same forward past the point X of thecylinder bore and ultimately to the discharge side of the pump or motor.i

In the stated description of the operation of the illusttated structuresso far given, they have been treated as pumps; but, it is obvious any ofthe piston blade seats 36, inward of the that said illustratedstructures are all capable of use as motors. They could be used asmotors with the piston turning in the same direction as it turns whenused'asa pump, but the structures will be more efficient as motors, if

the intake and discharge sides for the fluid shouldv be reversed. Inother words, if these illustrated structures should be used for a motorthe intake for the fluid should be where the discharge appears for thepump and the discharge where the intake appears for the pump. Of course,when any of these structures illustrated are used as a fluid motor,

then the coupling end of the piston shaft 25 would be properly coupledto the mechanism intended to be driven by the motor.

Having regard to the structure illustrated in the main views Figs. 1 to16 inclusive, attention has already been called to the fact 4 that thecylinder. end castings 24 are reciprocally alike, or rights and lefts.This same remark applies with equal force to the cylinder end liners 89,which carry the equalizing ducts l9 and 50. It follows that, if the twocylinder end liners 39 should be interchanged, or shifted to oppositeends of the cylinder, then, the direction of rotation of the ployed whenused as a pump. If the cylinder liners 39 were dispensed with and theend castings 24 provided with equalizing ducts 49 and 50, then the endcastings could be shifted to the opposite ends of the cylinder, and thesame remarks would apply as last above made in respect to the effect ofshifting said end liners 39. t

The same remarks apply, in substance, to the pair of end liners 61employed in the modification shown in Figs. 17 to 19, and to v thecylinder end castings 59 there illustrated.

In the structures here illustrated, the cylinders are stationary and thepistons rotated; but it will be understood, of course, that the pistonsmight be stationary and the cylinders made to rotate.

It will also be understood that many other minor changes might be madewithin the scope of my invention herein disclosed and pointed out in theclaims.

Because of the new features embodied in my improved pump or. motor, itis highly efficient. If used as a pump, it will require less power todrive it than other pumps of equal capacity, and, if used as a motor, itwill deliver'more power from a given head of fluid than other motors.

It is also obvious that its parts are all extremely simple, and hencethe pump or motor is cheap to make. It is also cheap to maintain inworking condition, due to the fact that all the parts subject to wearand-tear or to corrosion can be so easily made and replaced;

and, the durable.

What I claim is: v

1. In a rotary fluid pump or motor, the combination with a cylinderhaving fluid supply and discharge passages, of a piston having bladesmovable outwardly beyond its body, one of which two elements isstationary and the other rotative, and which two elements afford,between their walls, a loaded chamber concentric to the piston centerwhich loaded chamber communicates with said fluid supply and dischargepassages of the cylinder only underthe control of the piston blades, andwhich concentric loaded chamber has a radial depth, outward of thepistons body, equal to the extreme outward throw of the piston bladesand has an arcuate length equal to or greater than the arcuate distancebetween successive piston blades, whereby there will always be at leastone of said blades operating in said loaded chamber to efiect a sealbetween said fluid supply and discharge passages and while so operating,or under load, will receive no motion relative to the piston body, andwhich said cylinder has a continuous bore wall affording a continuousunbroken surface with which the outer ends of the piston blades contactfull length throughout the entire revolution of the rotating part of the.pump or motor.

2-. In a rotary fluid pump or motor, the combination with a cylinderhaving fluid supply and discharge passages, of a piston pump or motor,is therefore very having blades movable outward beyond its periphery,one of which two elements is sta tionary and the other is rotative, andwhich two elements-afford, between their walls, a loading chamberconstantly in communication' with said fluid supply passages of thecylinder, an unloading chamber constantly in communication with saidfluid discharge passages of the cylinder, both of which said chambersare non-concentric tothe piston center and a loaded chamber locatedbetween said loading and unloading chambers and communicating therewithonly under the control of the piston blades, which loaded chamher isconcentric to the pistons center and has a radial depth, outward of thepistons body, equal to the extreme outward throw of the piston bladesand an arcuate length equal to or greater than the arcuate distancebetween successive piston blades whereby there will always be at leastone of said blades operating in said loaded chamber to seal the samefrom the loading and 'unloading chambers and while so operating, orunder load, will receive no motion relative to the piston body, andwhich said cylinder has a continuous bore wall affording a continuousunbroken surface with which the outer ends of the piston blades.-contact full length throughout the entire revolution of the rotatingpart of the pump or motor.

'3. In a rotary fluid pump or motor, the

combination w1th a cylinder having fluid 5 periphery, one of which twoelements is stationary and the other is rotative, and which two elementsafiord, between their walls, a loading chamber constantly incommunication with said fluid supply passages of the cylinder and anunloading chamber constantly in communication withesaid fluid dischargepassages of the cylinder, both of said chambers being eccentric to thepistons center, and a loaded chamber located between said loading andunloading chambers and communicating therewith only under the control ofthe piston blades, which loaded chamber-is concentric to the pistoncenter and has a radial depth outward of the istons body Q equal to theextreme throw of the pistons blades and an arcuate length equal to orgreater than. the arcuate distance between successive piston blades, andwhich said cyl- ,inder has a continuous bore wall aifording a continuousunbroken surface with which the outer ends of the iston blades contactfull length throughout he entirerrevolution of the rotating part of thepump or motor.

' 4. In a rotary fluid pump or motor, the 3 combination with a cylinderhaving fluid supply and discharge passages, of a piston having bladesmovable outward beyond its periphery, one of'whichtwo elements is sta'tionary and the other is rotative, and which 5 two elements, affordbetween their walls, a loading chamber constantly in communication withsaid fluid supply passages of the cylinder and an unloading chamberconstantly in communication with said fluid discharge passa es oi thecylinder, both of which said chem cars are eccentric to the pistonscenter and sealed from interbommunication by the piston, and a loadedchamber located between said eccentric loading and unloading cham-.-bers, and communicating therewith only un der the control of thepiston blades, which loaded chamber is concentric to the pistons centerand has a radial depth, outward of the pistons 'body, equal to theextreme outward throw of the piston blades and an arcuate length equalto or greater than the arcuate distance between successive pistonblades, substantially as described and for the purposes set fortln-andwhich. said cylinder has a continuous bore wall affording a continuousunbroken surface with which the outer ends of the piston blades contactfull length throughout the entire/revolution of the rotati'ng part ofthe pump or motor. 5,-In a rotary fluid pump or motor, the combinationwith a cylinder having fluid sup ply and discharge passages, ofa'pistonhaving blades movable outwardly beyond its body, one of which twoelements is stationcry and the other rotative, and which two elementsafiord, between their walls, a loadedchamber concentric to the pistoncenter which loaded chamber communicates with said fluid supply anddischarge passages of the cylinder only under the control of the pistonblades, and which concentric loaded chamber has a radial depth, outwardof the pistons body, equal to the extreme outward throw of the pistonblades and has arcuate length equal to or greater than the arcuatedistance between successive piston blades, whereby there will always beat least one of said blades operatingin .saidloaded chamber to efiect aseal between said fluid supply and discharge passages and, while sooperating or under load, will receive no motion relative to the pistonbody and means for equalizing the fluid pressure on all surfaces of saidpiston blades while moving relative to the piston body.

6. In a fluid pressure pump or motor, the combination with a cylinderhaving fluid supply and discharge passages, loading and unloadingchambers and a loaded chamber concentric with the rotor of a pistonhaving blades seated in its body with freedom for movement outwardbeyond said bodys periphery, and which cylinder has'fluid ducts withwhich the inner ends of the piston blade seatscommunicate, in certainportions of the pistons' travel, for rendering fluid pressure availableto balance said blades when traveling through the loading and unloadingchambers of the pump or motor and to hold the blades in their outermostposition, when traveling through the concentric loaded chamber of thepump or motor.

7. In a rotary fluid pump or motor, the combination with a piston, of acylinder having end castings provided, on their inner profile faces,with fluid supply and discharge passages and end liners withperforations through which the fluid must pass in entering or leavingsaid cylinder, whereby said perforated liners will act as screens toexclude foreign materials which might otherwise break or injure thepump.

8. In a. rotary pump or motor, the combination with a piston, of acylinder having end castings provided with fluid supply and dischargevpassages on their inner profile faces an hich end ca'stingsarereciprocally alike on I ir said inner profile faces, whereby they can beshifted or interchangeably used at opposite ends of said cylinder, forpermittingthe rotary part o figthe motor to turn in opposite directionswithout change in the supply inlet or the dischargeoutlet of p profilefaces, with fluid supply andidischarge passages and having endlinersprovided with right and left perforations and right and left fluidpressure equalizing ducts on their inner outermost position while movingthrough profile faces" and which end liners are resaid concentric loadedchamber of the pump ciprocally alike on their said inner profile ormotor, substantially as described.

faces, whereby they can be interchanged and In tBStim I Y wh e f I ifiXmy Signature- 5 used at opposite ends of the cylinder, for per- THEODOREJ. PAGEL. I 70 mitting therotary part of the motor to turn in oppositedirections without change in the fluid supply inlet or the fluiddischarge outlet of the cylinder. 10. In a rotary fluid pump ormotor,the 75 combination with a cylinder and piston of waste ducts leadingfrom the annular spaces around the piston shaft, adjacent to itsstuffing boxes, to the fluid supply passages of the cylinder wherebythat annular space will 3a be subject to the pumping action and seepagepressure cannot accumulate at those points;

11. In a rotary fluid pump or motor, the combination with a pistonhaving blades,

movable outwardly beyond its body, of, a 36 cylinder having a continuousbore wall aflording a continuous unbroken surface with which'the outerends of the piston blades contact full length throughout an entirerevolution of the rotating part of the pump or to motor, and whichcylinder is provided with lateral fluid supply and discharge passages inboth of its end walls which only communicate with the interior of thecylinder through the end walls of the same, under the control W of saidblades.

12. In a rotary fluid pump or motor, the combination with a cylinderhaving fluid supply and discharge passages, of a piston having bladesmovable outwardly beyond its 1% body, one of which of said two elementsis stationary'and the other rotative and which two elements afi'ord,between their walls, a loaded chamber concentric to the piston 40center, which loaded chamber communicates with said fluid supply anddischarge passages of the cylinder only under the control of the pistonblades, and means for rendering discharge fluid pressure available onsaid blades 45 to hold the same in their outermost position while movingthrough said concentric loaded chamber of the pump or motor.

v 13. In a rotary-fluid pump or motor, the combination with a cylinderhaving fluid supply and discharge passages, of a piston having bladesmovable outwardly beyond its body, one of which said two elementsisstationary and the other rotative and which two 55 elementsafford,'between their walls, a loaded chamber concentric to the pistoncenter, which loaded chamber communicates with said'fluid supply anddischarge passages of the cylinder only under the control of the pistonblades, and means for rendering equal fluid pressure available on allsurfaces of said blades to balance the same while receiving I anymovement relative to the piston body, 65 and means for renderingdischarge fluid pres- 7 sure available to hold said blades in their

